Magnetic resonance imaging (MRI) is a modality for evaluating tissue structure and function. Several MRI techniques are routinely used in clinical and research settings to answer questions related to anatomy, physiology and pathology at acute and chronic disease stages. Of the many developmental sub-fields in MRI, one of the more rapidly growing areas concerns multi-channel radio frequency (RF) coils for signal transmission and/or reception. In particular, over the past decade, there has been widespread interest in implementing wireless RF solutions owing to several problems associated with wired RF coils.
Firstly, coaxial cables in wired RF coils impart a level of rigidity to the setup process and restrict the range of motion of both, the transmit-receive (Tx-Rx) and Rx-only coil components during setup. Along these lines, with increasing number of arrays (up to 128 channels), cable management becomes very complex. Baluns are required for each channel and cables must be routed efficiently in order to minimize coil interactions. Secondly, due to the switching of coil components in the course of a routine day on a clinical scanner (given the different anatomical body parts examined), the cables are also subject to induced stress over time compromising their elasticity, leading to increased wear and tear and potentially requiring frequent replacements. Thirdly, coaxial cables can play the role of an antenna capturing external noise and lead to a decrease in signal-to-noise ratio (SNR) of the acquired images. For these main reasons, implementing a wireless mode for the RF subsystem is highly desirable.